A reaction fanfiction in Fate Apocrypha could explore the characters' responses to various events. For example, how the Servants react to unexpected twists in the Holy Grail War. It might be interesting to see how characters like Siegfried or Mordred would react to a rule change in the war.
EMIYA often plays a key role in Fate Apocrypha fanfic. He can be a protagonist, guiding the story with his unique set of skills and experiences. His combat abilities and strategic thinking make him a formidable force in any fan - created scenario.
In Fate Apocrypha fanfic, EMIYA might be given new backstories or motives. This is because fanfic authors have the freedom to expand on the existing lore. They can delve deeper into his past as a hero, perhaps exploring his time as a hero before he became a Counter Guardian. This can add new layers to his character and make him more complex and appealing to readers.
An OC (Original Character) in Fate Apocrypha fanfiction can bring fresh perspectives. It allows fans to explore uncharted territories within the Fate Apocrypha universe. For example, an OC could be a new Servant with a unique backstory and abilities, which might interact with the existing characters in interesting ways. Fanfiction writers often use OCs to fill in the gaps they feel exist in the original story or to create their own unique story arcs that still fit within the overall theme and lore of Fate Apocrypha.
Another concept is a more comical crossover. Shirou tries to adapt to the different rules and magic in the Fate Apocrypha world. He constantly gets into funny situations as he misunderstands the local customs and magic systems. For example, he tries to cook using Apocrypha - style magic ingredients and chaos ensues.
One popular trope is the 'hidden power' trope. The OC might start off as an unassuming character but gradually reveals a powerful and unique ability that changes the course of the Holy Grail War. Another is the 'love interest' trope, where the OC becomes romantically involved with one of the canon characters, adding a new layer of drama to the story.
Naruto's character would fit in quite uniquely. His boisterous and positive personality would be a contrast to some of the more solemn characters in Fate Apocrypha. His ability to make friends easily could lead to some interesting alliances. For example, he might befriend some of the more morally ambiguous Servants and sway them towards a more positive path.
Archer from the Fate/stay night series is often a popular choice for crossovers. His cool and somewhat aloof personality can create interesting interactions with other servants.
The key features include a large and diverse cast of characters. Each character has their own backstory, motivation, and unique abilities, which makes the story complex and engaging. There are also multiple story arcs that interweave, creating a rich narrative.